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ASH1L gene

ASH1 like histone lysine methyltransferase

Normal Function

The ASH1L gene, also known as KMT2H, provides instructions for making an enzyme, called lysine-specific methyltransferase 2H, that is found in many organs and tissues of the body. Lysine-specific methyltransferase 2H functions as a histone methyltransferase. Histone methyltransferases are enzymes that modify proteins called histones. Histones are structural proteins that attach (bind) to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones (a process called methylation), histone methyltransferases control (regulate) the activity of certain genes. Lysine-specific methyltransferase 2H appears to turn on (activate) certain genes that are especially important for development of the brain.

Health Conditions Related to Genetic Changes

Autism spectrum disorder

At least seven ASH1L gene mutations have been identified in people with autism spectrum disorder (ASD), a varied condition characterized by impaired social skills, communication problems, and repetitive behaviors. Some ASH1L gene mutations associated with ASD change one building block (amino acid) in the lysine-specific methyltransferase 2H enzyme. Others delete genetic material in the ASH1L gene sequence or result in a premature stop signal that leads to an abnormally short enzyme. As a result of these mutations, the enzyme is nonfunctional. A lack of functional lysine-specific methyltransferase 2H enzyme disrupts histone methylation. The resulting changes in the expression of genes regulated by lysine-specific methyltransferase 2H affect brain development and increase the risk of ASD. Normal variations in other genes, as well as environmental risk factors, such as parental age, birth complications, and others that have not been identified, also affect an individual's risk of developing this complex condition.

More About This Health Condition

Other Names for This Gene

  • absent small and homeotic disks protein 1 homolog
  • ASH1
  • ash1 (absent, small, or homeotic)-like
  • ASH1-like protein
  • ASH1L1
  • histone-lysine N-methyltransferase ASH1L
  • huASH1
  • KMT2H
  • lysine N-methyltransferase 2H
  • probable histone-lysine N-methyltransferase ASH1L

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Eram MS, Kuznetsova E, Li F, Lima-Fernandes E, Kennedy S, Chau I, Arrowsmith CH, Schapira M, Vedadi M. Kinetic characterization of human histone H3 lysine 36 methyltransferases, ASH1L and SETD2. Biochim Biophys Acta. 2015 Sep;1850(9):1842-8. doi: 10.1016/j.bbagen.2015.05.013. Epub 2015 May 19. Citation on PubMed
  • Rogawski DS, Ndoj J, Cho HJ, Maillard I, Grembecka J, Cierpicki T. Two Loops Undergoing Concerted Dynamics Regulate the Activity of the ASH1L Histone Methyltransferase. Biochemistry. 2015 Sep 8;54(35):5401-13. doi: 10.1021/acs.biochem.5b00697. Epub 2015 Aug 25. Citation on PubMed or Free article on PubMed Central
  • Stessman HA, Xiong B, Coe BP, Wang T, Hoekzema K, Fenckova M, Kvarnung M, Gerdts J, Trinh S, Cosemans N, Vives L, Lin J, Turner TN, Santen G, Ruivenkamp C, Kriek M, van Haeringen A, Aten E, Friend K, Liebelt J, Barnett C, Haan E, Shaw M, Gecz J, Anderlid BM, Nordgren A, Lindstrand A, Schwartz C, Kooy RF, Vandeweyer G, Helsmoortel C, Romano C, Alberti A, Vinci M, Avola E, Giusto S, Courchesne E, Pramparo T, Pierce K, Nalabolu S, Amaral DG, Scheffer IE, Delatycki MB, Lockhart PJ, Hormozdiari F, Harich B, Castells-Nobau A, Xia K, Peeters H, Nordenskjold M, Schenck A, Bernier RA, Eichler EE. Targeted sequencing identifies 91 neurodevelopmental-disorder risk genes with autism and developmental-disability biases. Nat Genet. 2017 Apr;49(4):515-526. doi: 10.1038/ng.3792. Epub 2017 Feb 13. Citation on PubMed or Free article on PubMed Central
  • Wang T, Guo H, Xiong B, Stessman HA, Wu H, Coe BP, Turner TN, Liu Y, Zhao W, Hoekzema K, Vives L, Xia L, Tang M, Ou J, Chen B, Shen Y, Xun G, Long M, Lin J, Kronenberg ZN, Peng Y, Bai T, Li H, Ke X, Hu Z, Zhao J, Zou X, Xia K, Eichler EE. De novo genic mutations among a Chinese autism spectrum disorder cohort. Nat Commun. 2016 Nov 8;7:13316. doi: 10.1038/ncomms13316. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.